The fifth phase is the one that gives the castle its present appearance, and it constitutes the last important intervention of its history, which was a large scale militarization of the whole complex. All the structures built in this period are defensive elements, sturdy bastions protecting the rocks and older structures, and motivated by new defensive requirements. With the advent of gunpowder and gunnery, any attack would no longer lead to the base of the walls since it was not necessary to close in on the complex to submit it to siege, but only required blows from a distance. The perimeter walls defending the castle were no longer required to render difficult attack at the base with ladders, ropes and whatever else. Instead, what was required was resistance to the impact of cannon balls that would cause the structure to crumble and render it difficult for the defenders to move within.

The specific triangular form is designed to offer as minimum an impact surface as possible to the fire of the besiegers. The fact that these structures were built during a transition period between these two forms of siege warfare is indicated by the exceedingly high bastions, and the presence of portcullises (to render it easier to cast down boiling oil, stones or anything else on the attackers).

Astudy of historical documents tends to date this phase close to the viceregal period, since the sources dealing with the castles in the Aragonese period speak only of small repairs, while under the Caracciolo family, the castle seems to have been worthy of great attention and was a venue for very important events. The whole complex underwent great modifications whose objective was, above all, an increase of its military potential. In particular, new structures were added—CF 2. 3, 10, and 13---while a pentagonal defense was added around the base of CF 5.

After this phase, the castle underwent still other interventions, none of which rearranged its outward appearance. Most probably they were a series of internal modifications, datable from the XVII century, some traces of which might be found in the internal anterior portion, behind CF 15, to create a series of small quarters, perhaps prison cells.

Structure 2 (2001 ©Donato)

Structure 3 (2001 ©Donato)

Structure 13 (2001 ©Donato)

Structure 10 (2001 ©Donato)

Structure 15 (2001 ©Donato)